Additional Observations on the Development and Life-Histories of the Marine Food-Fishes, and the Distribution of their Ova

Extract

Since the previous communication to the Society by the author and Professor Prince, not a few dubious points have been cleared up, and, by the courtesy of the Fishery Board for Scotland, further investigations on the general subject carried out at the St Andrews Marine Laboratory. Under the former head may be mentioned the large unknown pelagic egg, with a spacious privitelline space, termed Ovum of Pleuronectid B. This has been proved by Mr E. W. L. Holt to be the egg of the Long Rough Dab, so that the ambiguity which has existed since the Trawling Expeditions of 1884 is now at an end. The larval and early post-larval stages of the species have already been described and figured. A more detailed series of observations have also been made on the development of the Lemon Dab or Lemon “Sole,” as it is somewhat ambiguously termed, showing how readily ova can be transmitted long distances, and the larval and post-larval stages reared subsequently. Formerly, only the ovarian egg of Miiller's Topknot was described and figured; now the fertilized and free-floating egg and its development have been studied. Like the egg of the Turbot and Brill, this has an oil-globule. The larva is tinted of a deep gamboge-yellow on head, trunk, and upper part of yolk-sac, while the oil-globule is conspicuous at the posterior and lower part of the yolk by an environment of the same bright hue.